ET:
- offers 100 more elemental defence to party, to himself 150 more in total, also 5% less cooldown to himself than other tanks
- awesome cubic, one that recovers 10% HP/MP per 10 sec also releasing debuff, the other give 7 sec of debuff inmunity + some pdef, mdef, shield def.
- a skill that drags enemies around himself and let them a short duration kind stun effect
- also has a chain hydra kind skill that drag enemies in a front line

Over all, PK will be better open pvp wise more pdef/mdef, more debuff resistance, and stay alive with noble sacrifice will be nice.
For oly ET is better, more damage mitigation, cubic regen a lot of mp, also less mp consumption and less cooldown on skill,

Offensive tanks pvp

SK:
- mass lightning strike , cooldown reduce to half, 30 sec... awesome
- frenzy: gives vanishing shock, our justice punishment, the ability to proc, 100% time, during frenzy duration, lightning strike effect. so it make a short range para, but less cooldown, so nice.
- gve pdef/mdef to party improve form now..

HK:
- reflect damage, and a lot. by himself has 10% armor, 15% passive, 5 % aura (10% at +11), 25% on frenzy, 10% with focus/raise shield, 5% more for activation skill, so, over all, has 35% permanent, 60% with frenzy ( 1 min, cooldown 5 min, half that with buff / cooldown reduction items) and another extra 15%-20% with proc skill, with the usual active / passive refelct augment will have over 100% reflect every 2minutes, so on OLy will be though..... cat eyes will increase it price

Over all, open pvp SK, its mass para skill will be insane, buffed and with some items will be cating it every 15 sec, maybe even more often

HK, on open pvp, will be also very good, most ppl dont use cat eye on mass pvp, and HK will be moving round, every 2 min with over 100% reflect damage... not bad. In oly, if you dont have a decent cat eye, and other reflect resistance gear, HK will be very hard to defeat.

All has it pro and cons, HK will not have its former pve damage, but will not be that bad either.
On other tanks i think an improvement, sadly no damage boost on pvp given...